Persons and in particular young children learning how to write, often grip hand held instruments used for writing, drawing and painting improperly. Absent instruction to the contrary, individuals will generally grasp a pencil in a manner that feels the most stable to him or her.
Beginning at age three and through adulthood, the most stable grasp that still allows precision and proper pencil pressure, is a dynamic tripod grasp. The dynamic tripod grasp requires separation of the radial and ulnar sides of the hand. The radial side of the hand, namely the thumb, index finger and middle finger, are generally referred to as the precision side of the hand. The ulnar side of the hand, namely the ring finger and little finger, are referred to as the power side of the hand.
To achieve a dynamic tripod grasp, the individual pinches the instrument between the distal pads of the index finger and thumb, and then rests the instrument on the lateral distal interphalangeal (DIP) joint of the middle finger. These three fingers together are the tripod. These three fingers supported by arches in the palm of the hand, utilize precise movements of rotation, flexion and extension to achieve the small movements needed for letter formation or other fine motor activities requiring accuracy. In addition, the space between the thumb and index finger, namely the web space, must be maintained in an open and circular manner to support the dynamic movements of the tripod fingers. The ulnar side of the hand stays in a flexed and quiet position so as to provide a stable base of support from which the tripod can move.
Many individuals develop improper grasping habits by gravitating towards seemingly more stable grasp patterns at the expense of precision. For example, a common improper grasp pattern is the thumb wrap grasp, in which the thumb overlaps the instrument. The result when using a pencil, is an inactive thumb that pulls in other muscles to compensate, and increased pencil pressure, decreased pencil control and increased hand fatigue when writing. Other common improper grasping patterns include hyperextension at the DIP joints of the thumb and index finger, which causes increased instrument pressure and a tight grasp, resulting in hand fatigue; power grasp in which the instrument is held in a fisted manner with the ulnar side of the hand toward the paper, resulting in decreased precision and increased instrument pressure; four-finger digital grasp in which all four finger pads touch a pencil on one side and the thumb pad opposes the fingers on the other side of the pencil, resulting in decreased pencil control and decreased pencil pressure; and internal rotation and adduction of the thumb, resulting in a closed web space, increased instrument pressure, increased hand fatigue and poor instrument control.
As a result of compensatory grasping patterns, learning how to write properly, legibly, neatly, efficiently, and with enough endurance to complete tasks within a typical time frame, is hindered. Furthermore, efficient use of other hand held instruments is impeded. In addition, thumb and finger joints can be subjected to unnecessary stress.
As exemplified by U.S. Pat. No. 1,879,456 to Parsons, U.S. Pat. No. 4,526,547 to Rusk, U.S. Pat. No. 5,143,463 to Pozil et al, U.S. Pat. No. 5,626,430 to Bistrack, U.S. Pat. No. 6,254,293 to Citrenbaum, and U.S. Des. Pat. No. 228,418, and Patent Application Publications 2002/0034411 to Rusk and 2003/0231917 to Geddes et al, and by the START RIGHT pencil grip, gripping aids, and in particular writing aids, that are mounted on hand held instruments are known. However, no prior art gripping aid is entirely satisfactory.
For example, the asymmetrical Pozil grip, which has an elongated body provided with three concave surface depressions to be grasped by the thumb, index finger and middle finger, and which is commercially made of soft rubber, does not adequately prevent thumb wrap, thumb internal rotation or index finger DIP joint hyperextension. Furthermore, it can be understood from col. 3, lines 51–57, of the Pozil et al patent, that the Pozil grip is intended to reduce dynamic finger movements and increase full hand and arm action. Although that result benefits an arthritic individual, it does not optimally benefit learning how to write properly.
Beneficially, the START RIGHT pencil grip includes a thumb wrap-preventing guard that extends from a proximal body end to a distal body end, and that is generally perpendicular to the throughbore at the distal body end. However, the START RIGHT pencil grip does not assure proper thumb and finger positioning.
There therefore continues to be a need for an improved gripping aid, and in particular a grip that assures proper positioning of the tripod fingers and keeps them in place. Beneficially, the gripping aid would assure fine motor control and dynamic movements of the tripod fingers. Moreover, it would be advantageous if the same gripping aid could be used by left handed and right handed users.